Mobile paging telephone call back system and method

ABSTRACT

A mobile paging telephone call back device determines and adds the appropriate prefix to a received call back number. The call back device includes a pager, a control unit, an automatic dialer, and a cellular telephone. The pager receives a page message from a paging system central controller. The control unit extracts a dialable telephone number from the page message, determines the appropriate prefix to be added to the telephone number, and adds the prefix to the telephone number. Using the telephone number with the added prefix, the automatic dialer completes a call back for the cellular telephone.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to mobile paging telephone call backsystems and methods. More particularly, the present invention relates tosystems and methods for adding appropriate prefixes to receivedtelephone numbers to permit automatic dialing of the telephone numbersby a mobile telephone device.

2. Description of Related Art

Today's mobile cellular telephones offer tremendous communicationadvantages for mobile consumers. Because cellular telephones oftenexhibit poor reception qualities and consume power quickly, however,cellular companies have begun to incorporate paging receivers intocellular telephones. With the paging receiver, the cellular telephonecan be turned off, conserving battery life, while the paging receiverremains on monitoring for calls. Battery life is conserved because thepower to energize a paging receiver is comparatively low. An example ofa mobile paging telephone call back device is disclosed in commonlyassigned U.S. Pat. No. Re. 33,417 ("the '417 patent"), entitled "MobilePaging Call Back System and Related Method," by Bhagat et al., thecontents of which are hereby incorporated by reference.

FIG. 1 is a block diagram of a mobile paging telephone call back device10, as described in the '417 patent. The mobile paging telephone callback device 10 includes a control unit 12 connected to a radio pager 14,a memory 16, a radio telephone interface 18, control switches 20, and anindicator 22. The radio telephone interface 18 is also connected to anintelligent automatic dialer 24, which is in turn connected to a mobileradio telephone 26.

The device 10 operates as follows: a caller wishing to reach asubscriber (a user of the mobile paging telephone device 10) calls apaging station (not shown), leaves a call back telephone number, and,typically, hangs up. The paging station then transmits the call backtelephone number over the air. The radio pager 14 receives the call backtelephone number and passes it to control unit 12. The control unit 12processes the number, stores it in memory 16, and displays it onindicator 22. A subscriber wishing to return the call presses a controlswitch 20, activating the automatic dialer 24 to dial the displayed callback telephone number.

Mobile paging telephone devices, like call back device 10, greatlyconserve the battery life of the cellular telephone, which, asdescribed, can be turned-off, then turned-on when a page comes in.Today's mobile paging telephone devices suffer, however, from onenagging disadvantage; they often cannot complete the call back becausethe call back telephone number lacks the appropriate prefix, such as anarea code or a "1", necessary to complete the return call. For example,a calling party may be unaware of the location of the subscriber andfail to include the prefix "1" and area code when he or she enters thecall back telephone number. This information may be necessary tocomplete a long distance dial back call. Conversely, the calling partymay unnecessarily include a "1" or an area code in the call backtelephone number, thinking the subscriber is away, when the subscriberis actually local. This problem is compounded in areas where dialingplans require a prefix, such as an area code, to complete even localcalls.

In each of the above situations, conventional mobile paging telephonedevices cannot automatically complete a call using the call back numberas received. Instead, the subscriber must manually dial all or part ofthe call back number including the appropriate prefix. If the subscriberdoes not know the appropriate prefix, he simply cannot return the call.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a mobile pagingtelephone call back system and method that substantially obviates one ormore of the problems due to limitations and disadvantages of the relatedart.

To achieve these and other advantages and in accordance with the purposeof the invention, as embodied and broadly described, the presentinvention provides, in a paging system central controller, a method oftransmitting a page message containing a call back number, comprisingthe steps of receiving a message from a caller; receiving an area coderepresenting the area code of the caller; determining whether thereceived message contains a dialable call back number; if the receivedmessage contains a dialable call back number, determining whether thecall back number has an area code; adding the received area code to thecall back number if the call back number does not have an area code orthe received area code does not match an area code of the call backnumber; and transmitting the received message including the call backnumber.

Further, the present invention provides a method of receiving a pagemessage containing a call back number on a mobile paging telephone callback device, comprising the steps of receiving an incoming message atthe mobile paging telephone call back device; extracting a call backnumber from the received message; receiving a system identificationnumber (SID) at the mobile paging telephone call back device;determining a roaming status of the mobile paging telephone call backdevice; determining an appropriate dialing plan based on the receivedSID; and determining a prefix for the call back number based on theappropriate dialing plan and roaming status of the mobile pagingtelephone call back device.

Additionally, the present invention provides a mobile paging telephonecall back device comprising means for receiving a page message includinga call back number; controlling means for determining an appropriateprefix to be added to the call back number; and means for displaying thecall back number with the appropriate prefix.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings which are incorporated in and constitute apart of the specification, illustrate presently preferredimplementations of this invention and, together with a generaldescription given above and the detailed description of the preferredimplementations given below, serve to explain the principles of theinvention.

In the drawings:

FIG. 1 shows a block diagram of a conventional mobile paging telephonecall back device;

FIG. 2 is a block diagram of a control unit included in a mobile pagingtelephone call back device according to a preferred embodiment of thepresent invention;

FIG. 3 is a block diagram of a paging system central controlleraccording to a preferred embodiment of the present invention;

FIG. 4 is a flow diagram illustrating processing operations of a pagingsystem central controller according to a preferred embodiment of thepresent invention;

FIG. 5 is a flow diagram illustrating processing operations of themobile paging telephone call back device according to the presentinvention; and

FIG. 6 is a flow diagram illustrating additional processing operationsof the mobile paging telephone call back device according to the presentinvention.

DETAILED DESCRIPTION

A preferred embodiment of the mobile paging telephone call back deviceof the present invention is similar to the conventional one describedabove, but preferably includes several changes in accordance with thepresent invention. As shown in FIG. 2, the control unit 12 of the mobilepaging telephone call back device of the present invention includesRoaming Status Determination ("RSD") application 32, Dialable TelephoneNumber Extraction ("DTNE") application 34, Dialing Plan Determination("DPD") application 36, Dialable Telephone Number Display ("DTND")application 38, dialing plan table 40, and processor 50. Applications32, 34, 36, and 38 are executed on processor 50. Processor 50 has accessto data stored in table 40, as well as memory 16 (FIG. 1). Preferably,processor 50 is of any known type capable of controlling theapplications 32, 34, 36, and 38 and performing the functions describedherein.

Upon receiving a page message, pager 14 activates telephone 26, which,upon initialization, receives a switch system identification number(SID) from the local cellular switch. RSD application 32 determines the"roaming" status of the mobile paging telephone device of the presentinvention, that is, whether the mobile paging telephone device is in aregion serviced by the subscriber's cellular carrier. Preferably, RSDapplication 32 compares the received SID with a prestored SID thatidentifies the subscriber's cellular carrier. If the received SID andprestored SID are the same, then the RSD application 32 determines thatthe call back device is not roaming. However, if the received SID andprestored SID are not the same, then the RSD application 32 determinesthat the call back device is roaming.

DTNE application 34 extracts the telephone numbers contained in receivedpage messages and stores them in memory 16. DTNE application 34recognizes dialable telephone numbers according to acceptable telephonenumber formats, such as the North American Numbering Plan and the WorldNumbering Plan. The formats recognized by DTNE application 34 can beupdated or modified "over the air" using conventional techniques. Forexample, a paging transmitter can transmit a group page messageincluding updated telephone formats to the call back devices. Anotherway of updating the recognized formats is to transmit the formatinformation over the cellular telephone for storage in the call backdevice.

Dialing plan table 40 stores dialing plans of various telephone regionslocated throughout predefined geographic regions, such as, for example,North America. Each dialing plan includes the proper telephone numberformat for placing calls within the predefined geographical region. Thedialing plans are indexed according to SID and can be updated "over theair" using conventional techniques such as described above.

DPD application 36 determines the dialing plan corresponding to theregion in which the subscriber is located. DPD application 36 finds theappropriate dialing plan by searching the dialing plan table 40according to the received SID. When the appropriate dialing plan isfound, dialing plan table 40 makes the dialing plan available to DTNDapplication 38.

Based on the dialing plan determined by DPD application 36 and theroaming status determined by RSD application 32, DTND application 38formats the received call back telephone number by adding to that callback telephone number any prefixes necessary to complete the call, anddisplays the formatted telephone number on indicator 22. For example, ifthe dialing plan requires an area code as a prefix to complete a localcall, then DTND application 38 checks whether the area code has beenincluded in the received call back number and, if not, adds the areacode. With the telephone number formatted, the subscriber canautomatically dial the call back number by, for example, activating asingle switch or pressing an appropriate function key.

FIG. 3 shows a block diagram of a paging system central controller 70,which transmits page messages to the call back device of the presentinvention. Generally, central controller 70 is similar to conventionalpaging central controllers, such as the Universal Messaging System("UMS"), owned and operated by SKYTEL® of Washington, D.C., except asmodified herein in accordance with the present invention. As shown inFIG. 3, paging system central controller 70 includes I/O module 72,memory 74, database 76, and controller 78, which are all connected tobus 86.

I/O module 72 prompts a caller to enter information via input 90,including the subscriber's personal identification number ("PIN") and acall back number. In accordance with conventional techniques, I/O module72 also receives on input 90 an Automatic Number Identification ("ANI")from the telephone carrier carrying the caller's call. The ANIpreferably includes at least an area code, and may include anyadditional digits, in accordance with a telephone numbering format. I/Omodule 72 outputs on output 92 a page message to a paging transmitter(not shown), which transmits the page message to the subscriber.

Memory 74 stores information received from I/O module 72, including callback telephone numbers and ANIs. Database 76 stores records ofinformation corresponding to each subscriber.

Controller 78 processes the received page message and includes processor80, Dialable Telephone Number Processing ("DTNP") application 82, andArea Code Processing ("ACP") application 84. Applications 82 and 84 areperformed on processor 80, which is of any known type capable ofperforming the functions described herein. DTNP application 82determines whether the received page message contains a dialabletelephone number. ACP application 84 determines whether the dialabletelephone number includes an area code and, if so, compares the areacode with an area code in the received ANI to determine whether theymatch.

FIG. 4 shows a flow diagram describing the operation of paging systemcentral controller 70 for transmitting a page message in accordance witha preferred embodiment of the present invention. Initially, a caller (orpaging party) wishing to page a subscriber dials into paging systemcentral controller 70 (step 102). The paging system central controller70 prompts the caller to identify the subscriber to be paged byrequesting the caller to enter the subscriber's PIN (step 104). Afterthe caller identifies the subscriber, the paging system centralcontroller 70 prompts the caller to enter a call back telephone number(also step 104). In accordance with conventional techniques, thetelephone carrier handling the call automatically supplies to the pagingsystem central controller 70 the ANI, preferably identifying at leastthe area code from which the caller is calling (step 106).

DTNP application 82 of the paging system central controller 70 thenexamines the message (step 108) to determine whether the page messageincludes a dialable telephone number (step 110). DTNP application 82recognizes dialable telephone numbers according to acceptable telephonenumber formats similar to DTNE application 34 described above. If thepage message does not contain a dialable telephone number, the pagingsystem central controller 70 proceeds to transmit the message to thesubscriber without modifying the message (step 118).

If the message does contain a dialable telephone number, ACP application84 of the paging system central controller 70 determines whether thetelephone number includes an area code (step 112). If no area code isincluded, the paging system central controller 70 adds the area codethat was part of the ANI and supplied by the telephone carrier as aprefix to the telephone number. Controller 70 preferably marks the areacode prefix by, for example, enclosing the area code in brackets (step116). The paging system central controller 70 then transmits a pagemessage, including the bracketed area code and telephone number, to thesubscriber (step 118).

If, in step 110, the dialable telephone number does include an areacode, the paging system central controller 70 preferably determineswhether the area code included in the received telephone number matchesthe area code received from the telephone carrier (step 114). This stepis included to verify the area code, but could be deleted. If the areacodes match, then the page message, including the received telephonenumber, is transmitted to the subscriber (step 118). If, in step 114,the area codes do not match, the paging system central controller 70adds the area code supplied by the telephone carrier, again, preferablymarked in brackets, to the page message (step 116) and transmits to thesubscriber the modified page message, including the bracketed area code,the originally received area code (unbracketed), and the receivedtelephone number (step 118). Both area codes are transmitted to allowthe subscriber to select the one he believes is correct.

FIG. 5 shows a flow diagram describing a preferred operation of the callback device of the present invention. Initially, pager 14 receives amessage transmitted from the paging system central controller 70 (step202) and determines whether cellular phone 26 is turned on (step 204).If the cellular phone 26 is not on, pager 14 turns on the cellular phone26 (step 206). In accordance with conventional techniques, duringinitialization of the cellular phone 26, cellular phone 26 receives anSID from the local cellular switch and determines the roaming status ofthe call back device in the manner described above (step 208). Based onthe received SID, DPD application 36 of the call back device retrievesthe appropriate dialing plan (step 210), as also described above. Thecall back device extracts the dialable telephone number from thereceived page message and determines the appropriate prefixes accordingto the dialing plan and roaming status (step 212). The telephone numberis then displayed on indicator 22 along with the appropriate prefixes(step 214). As described in the incorporated U.S. Pat. No. Re. 33,417,the control unit 12 may perform steps to "verify" the received telephonenumber. However, these verification steps need not be performed inaccordance with one embodiment of the present invention.

FIG. 6 shows a flow diagram illustrating operation of the call backdevice where the call back device, in step 212 above, determines thatthe appropriate prefix includes an area code. If the call back devicedetermines that an area code is required to complete the call backoperation (step 302) and the page message includes both an unbracketedarea code and a bracketed area code (step 304), both area codes aredisplayed on indicator 22 along with the call back number (step 306).The subscriber can select the area code that he believes will completethe call back using, for example, a switch 20 included for this purpose(step 308). If only a single area code is included in the page message,e.g., a bracketed or unbracketed area code, then that area code isdisplayed along with the call back telephone number on indicator 22(step 310).

While there has been illustrated and described what are at presentconsidered a preferred implementation and method of the presentinvention, it will be understood to those skilled in the art thatvarious changes and modification may be made, and equivalents may besubstituted for elements thereof without departing from the true scopeof the invention.

In addition, many modifications may be made to adapt a particularelement, technique, or implementation to the teachings of the presentinvention without departing from the central scope of the invention. Forexample, applications 32, 34, 36, and 38 preferably comprise softwareprocedures, such as microcode, executed by processor 50 to perform thespecified functionality. However, in an alternative embodiment, thisfunctionality can be implemented in electronic circuitry in accordancewith conventional techniques. Therefore, it is intended that thisinvention not be limited to the particular embodiments and methodsdisclosed herein, but that the invention include all embodiments fallingwithin the scope of the pendant claims.

What is claimed:
 1. In a paging system central controller, a method oftransmitting a page message containing a call back number, comprisingthe steps of:receiving a message from a caller; receiving an area coderepresenting the area code of the caller; determining whether thereceived message contains a dialable call back number; if the receivedmessage contains a dialable call back number, determining whether thecall back number has an area code; adding the received area code to thecall back number if the call back number does not have an area code orthe received area code does not match an area code of the call backnumber; and transmitting the received message including the call backnumber.
 2. A method according to claim 1, wherein the received area codeis added to the call back number in marked fashion.
 3. A methodaccording to claim 1, wherein a dialable telephone number is determinedaccording to the North American Numbering Plan.
 4. A method according toclaim 1, wherein a dialable telephone number is determined according tothe World Numbering Plan.
 5. A method according to claim 1, wherein adialable telephone number comprises one of a seven digit number and aten digit number.
 6. A method according to claim 1, wherein a dialabletelephone number contains a number of digits, in accordance with theWorld Numbering Plan.
 7. A method of receiving a page message containinga call back number on a mobile paging telephone call back device,comprising the steps of:receiving an incoming message at the mobilepaging telephone call back device; extracting a call back number fromthe received message; receiving a system identification number (SID) atthe mobile paging telephone call back device; determining a roamingstatus of the mobile paging telephone call back device; determining anappropriate dialing plan based on the received SID; and determining aprefix for the call back number based on the appropriate dialing planand roaming status of the mobile paging telephone call back device.
 8. Amobile telephone paging call back device comprising:means for receivinga page message including a call back number; controlling means fordetermining an appropriate prefix to be added to the call back number inaccordance with a system identification number (SID); and means fordisplaying the call back number with the appropriate prefix.
 9. A mobilepaging telephone call back device according to claim 8, wherein saidcontrolling means includes:means for extracting the call back numberfrom the page message; and means for determining an appropriate dialingplan based on the SID.
 10. A mobile paging telephone call back deviceaccording to claim 9, further comprising:means for storing a pluralityof dialing plans.
 11. A mobile paging telephone call back deviceaccording to claim 9, further including:memory means for storingextracted telephone numbers.
 12. A mobile paging telephone call backdevice according to claim 8, wherein the appropriate prefix isdetermined according to a dialing plan.
 13. A mobile paging telephonecall back device according to claim 8, wherein the appropriate prefixincludes an area code.
 14. A mobile paging telephone call back deviceaccording to claim 13, wherein the area code comprises one of aplurality of area codes selected by a subscriber to be dialed with thecall back number.
 15. A mobile paging telephone call back deviceaccording to claim 8, further comprising:a mobile telephone forreceiving and placing telephone calls; and means for automaticallydialing the appropriate prefix and call back number.
 16. A mobile pagingtelephone call back device according to claim 15, wherein the receivingmeans activates the mobile telephone when the receiving means receives apage message.
 17. The mobile paging telephone call back device accordingto claim 8, wherein said controlling means includes:means for extractingthe call back number from the page message; and means for determining aroaming status based on the SID.
 18. A mobile paging telephone call backdevice according to claim 17, wherein said controlling means determinesthe appropriate prefix according to the roaming status of the call backdevice.
 19. A method of receiving a page message containing a call backnumber on a mobile paging telephone call back device, comprising thesteps of:receiving an incoming message at the mobile paging telephonecall back device; extracting a call back number from the receivedmessage; receiving a system identification number (SID) at the mobilepaging telephone call back device; and determining an appropriate prefixfor the call back number based on the SID.
 20. The method according toclaim 19, further comprising the step of adding the appropriate prefixto the call back number.